The National Electrical Code (NEC) requires that electrical wires and cables mounted within a wall structure must be at least one-and-one-quarter (1.25) inches behind the inner surface of the wall board. This code provision is intended to reduce the likelihood that a nail or other sharp implement would penetrate or damage the conductor insulation and potentially cause an electrical fire. The NEC further requires that a cable is secured at the 1.25 inch offset within 12 inches of an electrical junction box or other fitting, and at intervals of not more than 4.5 feet along a wire run.
A number of devices have been developed to implement the NEC requirement for a 1.25 inch offset, as described in the following exemplary patents:
U.S. Pat. No. 5,067,677 to Miceli is for a Wire Harness. This device is to be mounted on the face of a wall stud for holding a number of wires between the surfaces of a wall. The device has one arm for mounting to a stud and a second arm for attaching wires. A series of clips are placed along the second arm for receiving and holding wires.
U.S. Pat. No. 5,141,185 to Rumbold et al. is for a Wiring Clip. This patent discloses a clip having an L-shaped portion to be secured to a stud and a strut and hinged arm remote from the L-shaped portion, the arm is adapted for being folded and locked around several wires.
U.S. Pat. No. 5,587,555 to Rinderer is for a Conductor Holding Device. This conductor holder has a support member having two perpendicular arms, one arm for being affixed to a stud and the other arm being formed with one or more holes. A clamp having a leg and a head is mounted with the leg through the one hole in the arm and the head holding the conductor at a fixed distance from a wall surface.
U.S. Pat. No. 8,371,540, U.S. Pat. No. 8,387,927 and U.S. Pat. No. 8,746,633 to the present inventor are each for Cable Positioning Brackets. These three patents represent earlier inventions of brackets for holding a series of conductors at a selected distance from a wall surface.
U.S. Pat. No. 8,496,211 to Rinderer is for a Self-Correcting Conductor Positioning Bracket. This bracket includes a mounting portion shaped to permit fastening to a wall stud and an angularly oriented support portion for contacting the wall stud to resist displacement of the bracket. The conductor is placed in an aperture between a retainer plate and a positioning plate, the aperture being closed by a closing member.